Insoles, in particular insertable insoles, for shoes have numerous functions. They improve the wearing comfort of shoes, e.g. by padding out the places facing the sole of the foot or by the provision of damping elements. They are also used in the medical sector to correct faults in the gait of a person or to relax or stabilize the foot.
There are also insoles that vent the interior of the shoe to counter unpleasant odors developing in the interior of the shoe. In particular with sports persons and people with heavy sweat formation, human exudation in the interior of the shoe leads to a possible strong odor which can be largely compensated by appropriately venting the interior of the shoe.
Due to the described general problems, numerous patent documents deal with the formation of special shoe insoles which increase the wearing comfort of shoes or serve medical purposes.
For example, in patent specifications U.S. Pat. No. 5,404,659 and U.S. Pat. No. 6,301,807 insoles are described which, due to a filled out insole arch or an insole arch provided with supporting elements, cause a proprioceptive effect on the wearer of a shoe with such an insole, thereby reinforcing a foot in its structure, whereby, for example, the risk of injury is reduced.
Numerous patent specifications and applications deal with the ventilation of the interior of the shoe. For example, applications JP-11032809A and JP-2000106908A show the inner ventilation of shoes, whereby the ventilation in both cases is provided by a pump integrated into the insole. In the application document JP-2000106908A the ventilation system also exhibits a duct, connected to the pump, and having ventilation ports, through which the air in the pump is pumped upon compression thereof into the interior space of the shoe. Furthermore, there are also cypress chips in the pump which are intended to aromatize the ventilating air.
FR-A-2 395 719 discloses an insole which is substantially adapted to the profile of a human foot and has, in the mid-foot region, an elastically deformable dome-like arch that faces the foot and includes a venting port.
EP-0 903 984-B1 shows a configuration of a shoe internal ventilation system, consisting of a shoe outsole, an insole and a corresponding midsole. In this respect the invention exhibits air chambers between midsole and shoe outsole in the front section of the foot, the air from the chambers being passed into the shoe interior through holes in the insole in the front foot section during movement due to deformation in said sections.
EP-1 536 710-A1 shows an insertable insole made of an elastic plastic material with elastically deformable arch with punched-in venting ports and radially running grooves on the underside, through which the air ventilated out of the interior of the shoe is exchanged with outside air.
Since a shoe insole is a mass-produced article, it is especially important to keep the technical effort and the financial manufacturing costs of such an article as low as possible. At the same time the article should be of a constant high quality.